Designing Molecules for Metal−Metal Electronic Communication: Synthesis and Molecular Structure of the Couple of Heterobimetallic Isomers [η⁶-(2-Ferrocenyl)indene]-Cr(CO)₃ and [η⁶-(3-Ferrocenyl)indene]-Cr(CO)₃

The heterobinuclear isomers [η6-(2-ferrocenyl)indene]-Cr(CO)3 (1) and [η6-(3-ferrocenyl)indene-Cr(CO)3 (2) have been prepared and the crystal structure determination showed that the Fe(C5H5) and Cr(CO)3 groups in the two molecules are disposed in different conformations with respect to the Cp-indene bridging ligand, cisoid in 1 and transoid in 2. Preliminary electrochemical (CV) and spectroscopic (IR and near-IR) results obtained for the corresponding monooxidized 1+ and 2+ demonstrate the existence of stronger electronic coupling in 1+ than in 2+.